Solvent extraction of rhodium from aqueous solution of Rh(III)-Sn(II)-Cl- system by TBP

In this paper, the results of a systematic study on the solvent extraction of rhodium with TBP in hydrochloric acid are given. The optimum extraction conditions are as follows: The amount of added stannous chloride is four ti mes that of Rh according to the mole ratio of Sn and Rh, the temperature of complex reaction 60 degrees C, aging time 2 h, phase ratio 1:1, contact ti me 5 min. A highly efficient method of stripping Rh from the loaded organic phase of TBP is also proposed. The percentage of stripping may reach to 10 0% through one stage with 4 M hydrochloric acid containing chlorine. The me chanism of extracting Rh(III) with the addition of stannous chloride is des cribed and the reaction equation of extraction is deduced. (C) 1998 Elsevie r Science B.V. All rights reserved.